Discovery creates configuration items (CI) and CI relationships for physical and logical storage components attached directly to application and database servers or by fibre channel switched fabric in a multi-path configuration.

Direct attached storage

In this example of direct attached storage (DAS), a SCSI drive with two partitions, /dev/sda1 and /dev/sda2, is attached to a Linux host. The /dev/sda1 partition is bootable and supports the system software. The /dev/sda2 partition contains a logical volume configured as a storage pool and mounted to the Linux root file system by Logical Volume Management (LVM). The storage pool uses only 1.5GB of the partition, leaving 13GB of storage available for additional logical volumes.
Figure 1. Direct attached storage example
Direct attached storage DAS example
Table 1. CIs and relationships created for direct attached storage (DAS)
Configuration item Description Tables Key reference and Relationships
/dev/sda SCSI physical storage device
  • [cmdb_ci_disk]
  • [cmdb_ci_storage_device]
  • [cmdb_rel_ci]
 [cmdb_rel_ci]
  • Provides: /dev/sda
  • Provided by:/dev/sda1
[cmdb_rel_ci]
  • Provides: /dev/sda
  • Provided by:/dev/mapper/lvm-root-333-0
/dev/sda1 Partition 1 on the SCSI storage device
  • [cmdb_ci_partition]
  • [cmdb_ci_storage_volume]
  • [cmdb_ci_file_system]
  • [cmdb_rel_ci]
 [cmdb_ci_file_system]
  • Mount point: /boot
  • File system: Ext4
[cmdb_rel_ci]
  • Provides: /dev/sda
  • Provided by:/dev/sda1
/dev/sda2 Partition 2 on the SCSI storage device
  • [cmdb_ci_partition]
  • [cmdb_ci_storage_pool_member]
 [cmdb_ci_storage_pool_member]
  • Pool: /dev/mapper/lvm-root-333-0
  • Storage: /dev/sda2
/dev/mapper/lvm-root-333-0 Linux logical volume, mapped with LVM to a physical disk storage partition.
  • [cmdb_ci_storage_device]
  • [cmdb_ci_storage_volume]
  • [cmdb_ci_file_system]
  • [cmdb_ci_storage_pool]
  • [cmdb_ci_storage_pool_member]
  • [cmdb_ci_lvm_pool]
  • [cmdb_ci_lvm_pool_member][cmdb_rel_ci]
 [cmdb_ci_file_system]
  • Mount point: /
  • File system: Ext4
[cmdb_rel_ci]
  • Provides: /dev/sda
  • Provided by:/dev/mapper/lvm-root-333-0
[cmdb_ci_storage_pool_member]
  • Pool: /dev/mapper/lvm-root-333-0
  • Storage: /dev/sda2

Multipath fibre channel storage

In this example of a fibre channel storage area network (SAN), two physical storage devices, mpatha and mpathb, are attached to a Linux host through fibre switches, which provide failover capabilities. The mpatha drive contains two partitions, mpatha1 and mpatha2. The first partition is mounted directly to /boot on the Linux host. Three logical volumes are mapped to the mpatha2 partition and to the physical device mpathb. The logical volumes are mounted as Ext4 file systems in folders on the Linux root structure. This example shows the CIs that Discovery manages for each component and the mounting points for the logical volumes on the Linux host.

Figure 2. Multipath fibre channel storage example
Multipath fibre channel storage example

Switched fibre fabric details

Discovery creates CIs for the logical sub-components in NAS and SAN environments, such as fibre channel disks and pool components, as well as for host bus adapters (HBA) and physical block storage. In multipath environments, Discovery creates CI relationships within the switched fibre fabrics that connects the Linux host to the physical storage devices. In this diagram, the fibre fabrics have redundant paths that the SAN environment can use for failover if connections fail.

Figure 3. Fibre fabric redundant paths
Fibre fabric redundant paths